Why Are Drone Strikes Being Used More Often?
I suspect it's blowback. When people at Pentagon desks were attacked on 9/11, some of them decided to seek revenge and do it themselves. (I was inspired by this article.)
Blowback goes both ways.
The news coverage on 9/11 included videos of celebrations in the mideast. Those videos disappeared from the airwaves but I suspect they're stored on Pentagon computers and being analyzed using face-recognition software. (This would probably be faster if they were publicly available.)